Louis René Beres is a professor of Political Science at Purdue UniversityAll of America's national security strategy on counterterrorism is based, in part, on a single core assumption: that our terrorist enemies are plainly and uniformly "abnormal." Significantly, however, such presumptively stark polarities between normal and abnormal, good and evil, represent a debilitating caricature. In order to better understand and combat these enemies, we must first learn to acknowledge that even "normal" individuals can sometimes do us great harm.What does this mean? By definition, at least, psychopathology and normalcy would appear to be mutually exclusive. Yet some of our most insightful thinkers have reasoned otherwise. In these examples, they have willingly looked beyond the seductive veneers of orthodox psychological investigation.Sigmund Freud wrote about the "Psychopathology of Everyday Life" (1914) while tracing some intriguing connections between "the abnormal" and "the normal," and was genuinely surprised to learn just how faint the line of demarcation could be. More precisely, in exploring parapraxes, or slips of the tongue, a phenomenon that we now conventionally call "Freudian slips," he concluded that certain psychopathologic traits could occasionally be discovered in normal persons....